Prevalence of Methicillin-Resistant Staphylococcus aureus Skin and Nasal Carriage Isolates from Bovines and its Antibiogram

Aim: This study was conducted to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in cattle and buffalo and to study their antibiotic resistance pattern.
Materials and Methods: A total of 136 samples (skin and nasal swab) from cattle and buffalo were collected. MRSA was identified by conventional bacterial culture techniques which were further confirmed by amplification of S. aureus-specific 16S rRNA by polymerase chain reaction (PCR). The isolates were further analyzed for the presence of mecA gene by PCR. The antimicrobial susceptibility profiling was performed by disc diffusion method.
Results: The prevalence of MRSA in the current study was 28.57% and 34.28% in cattle nasal and skin swab, respectively, with an overall prevalence of 31.43% MRSA among cattle. Buffalo nasal and skin sample showed MRSA prevalence of 54.55% and 39.4%, respectively, with 46.9% overall prevalence. PCR could detect mecA gene in 36.4% and 58% MRSA isolates from cattle and buffalo, respectively. Antimicrobial susceptibility test found MRSA resistant to penicillin and oxytetracycline (88% each), cefoxitin (75%), cotrimoxazole (62%), and amoxyclav (50%). 100% sensitivity was observed against ciprofloxacin, amikacin, chloramphenicol, and gentamicin. Three (16.7%) MRSA isolates from buffalo were found resistant to vancomycin.
Conclusion: Cattle and buffalo were identified as a potential carrier of MRSA in Bihar (India). The isolation of vancomycin-resistant S. aureus (VRSA) in the current study indicates the emergence of VRSA in animal population which may be transmitted to the human beings working in close contact to the animals.